1, She is keen on travelling to Australia with her friends. (enjoys)

=> She enjoys travelling to Australia with her friends

2. It is necessary for us to protect our environment

=> We have to protect our environment

3 . He started working in this company five years ago

4 . Eating too much sugar leads to health problems

Ex 2 :

1 . If I weren't you , I would recycle these plastic carrier bags

2 . The books are arranged on the shelf everyweekend by her

3 . Because of an outbreak of Coronavirus , student had to stay at home

4 . I woke up later than my wife this morning

EX1

1, She enjoys travelling to Australia with her friends.

2, We have to protect our environment.

3, He started working in this company five years ago.

4, Eating too much sugar can lead to health problems.

EX2

1, If I were you, I would recycle these plastic carrier bags.

2, The books on the shelf are arranged by her every weekend.

3, Because of an outbreak of Coronavirus, students had to stay at home.

4, I woke up later than my wife this morning.

hoặc I didn't wake up as early as my wife this morning.